A. Diversion to Real Estate: While this can happen, it still involves some economic activity and might generate taxes (though potentially not on the full value of the transaction if black money is used).

B. Investment in Unproductive Activities: This can hurt the economy, but the government loses tax revenue regardless of the type of investment if it's funded by black money.

C. Donations to Political Parties: This is a concern, but the lost tax revenue likely outweighs the impact of such donations.

D. Loss of Revenue: Black money, by definition, avoids taxes. This directly reduces the government's income, limiting its ability to fund public services, infrastructure, and social welfare programs.

Tax evasion through black money creation significantly hinders the government's ability to function effectively and meet the needs of its citizens. This is why it's a major concern.